Device Removal forces Reboot

[Harald Rudell]

Have a pool on a usb device, unplug and replug the cable
Note: sometimes macOS assigns a new devicename, ie. /dev/disk3 replacing /dev/disk2. It is unclear if that affects zfs

zpool online z51 media-30E3C185-3FC7-4608-94FB-43EC73D4D0C0
Vanilla zfs command hangs

zpool clear z51
The openzfsonosx recommended method hangs

zpool status
pool: z51
state: UNAVAIL
status: One or more devices are faulted in response to IO failures.
action: Make sure the affected devices are connected, then run 'zpool clear'.
see: http://zfsonlinux.org/msg/ZFS-8000-HC
scan: none requested
config:
NAME STATE READ WRITE CKSUM
z51 UNAVAIL 0 0 0 insufficient replicas
media-30E3C185-3FC7-4608-94FB-43EC73D4D0C0 REMOVED 0 0 0

errors: 4 data errors, use '-v' for a list

http://zfsonlinux.org/msg/ZFS-8000-HC
instructs a reboot

This simple error that is likely to occur should be recoverable with less than a system reboot